This patch is based on the lm_sensors project CVS, from revisions 1.45 and 1.1
of lm75.c and lm75.h, respectively.

The patch fixes the conversion routines (according to datasheet) and moves
them into a header file - as these conversions can be used by several drivers
which emulate LM75s as subclients.  Also, temps are now reported in 1/1000 C
in sysfs as per documentation.